High-voltage electrical equipment or switchgear used today in electric energy distribution facilities for operating and/or protecting power grid comprise different compartments, such as the cable compartment, for example, which can receive connection cables or provide them with an outlet towards other distribution facilities.
Measuring, control and protecting means such as, for example, voltage sensors, voltage transformers, means for receiving/transmitting signals through PLC, means for detecting partial discharges, current sensors, etc., can also be installed in the cable compartment of a piece of electrical equipment.
These measuring, control and protecting means such as, for example, means supplying voltage and intensity values, such as toroidal inductive sensing elements for measuring intensity, and resistive/capacitive sensing elements for measuring voltage, are installed in the connection between the aforementioned cables and the high-voltage electrical equipment by means of connectors (for example, T-connectors) installed in situ, since the cables are previously installed. The captured signals are conditioned and processed in an electronic data acquisition system for protection, measurement and/or control. Therefore, in a distribution facility with several pieces of high-voltage electrical equipment installed therein, each of these pieces of electrical equipment comprises measuring, control and protecting means installed in the cable compartment, the signals captured by each of the measuring, control and protecting means being received by electronic relays which are integrated with the high-voltage electrical equipment itself. Therefore, each piece of high-voltage electrical equipment is generally provided with measuring, control and protecting means, as well as an electronic relay.
The measuring, control and protecting means are installed in situ once the connectors of the cables are installed, i.e., the measuring, control and protecting means are installed, set and checked on site, so errors in installing the means due to incorrect wiring of the ground grids, polarities, etc., would not occur. Likewise, each of the pieces of electrical equipment comprises its own electronic relay associated with its own measuring, control and protecting means, which involves the need of using at least one measuring, control and protecting means for each piece of electrical equipment arranged in a distribution facility, which leads to large pieces of electrical equipment and ultimately to a larger space required for the distribution facility, more extensive wiring, as well as higher costs.
In this sense, some examples of patents relating to such connections with T-connectors installed in the cable compartment can be mentioned:
Patent Application US20110025342A1 relates to a T-connector which, on one hand, can be connected to a bushing of a piece of electrical equipment through the first open end thereof. Likewise, the connector can be connected through the second open end thereof to a piece of equipment or said second open end can be insulated by means of a cap. The third open end is configured for receiving a power cable and a voltage sensing point is also arranged on this third end of the connector.
International Patent Application WO02080308A2 also relates to a connection system by means of a T-connector which allows sensing the intensity and voltage at the same point of connection between the cable and the electrical equipment. The system comprises a toroidal inductive sensing element for measuring intensity, a resistive sensing element for measuring voltage, a shielded connector, a fixed connection base (bushing of the electrical equipment) and a piece of electronic signal acquisition equipment. The intensity sensing element is supported on the fixed connection base, and the voltage sensing element is integrated in the separable T-connector, specifically at one of the open ends thereof, without changing the characteristics of the high-voltage connection.
Other examples include International Patent Application WO03107560A1, Utility Model ES1075987Y and Patent EP1309098B1, which also relate to solutions for the connection of measuring, control and protecting means in the cable compartment of a piece of high-voltage electrical equipment.
Patent EP2253963B1 relates to a solution for the connection of measuring, control and protecting means with the main set of bars of a piece of high-voltage electrical equipment. It relates to a specific connection with an adapted connector which, as a result of several connection interfaces, allows establishing an electrical connection by contact between planar surfaces. Such specific connection is developed to be used in sets of bars having a planar configuration, i.e., a non-standard configuration. Therefore, the object of said patent EP2253963 B1 is to simplify the connection of an electric magnitude measuring device with an element of a power line of the types including a connecting bar, cable or terminal, the connection interface of which is planar and compressible. Such connection therefore has the drawback of being able to be used only in facilities with sets of bars and connecting elements with a specific non-standard configuration, which makes the distribution facility more costly.